1. Field of the Invention
The present invention relates to an air cleaner for filtrating an air flowing in an intake system of an internal combustion engine.
2. Related Art
In an internal combustion engine, there may cause such a case as that an evaporated and gasified fuel flows inside an air cleaner from an engine side. In a conventional art, in order to adsorb such gasified air, an adsorbing member (or adsorbent) is disposed in the air cleaner in addition to a filter element.
For example, in an air cleaner disclosed in Japanese Patent Unexamined Application (KOKAI) Publication No. 2001-336454, a plurality of ribs are formed, so as to extend in parallel, to an inner surface of a housing of the air cleaner, and the adsorbing member is disposed between these ribs.
Furthermore, an air cleaner disclosed in Japanese Patent Unexamined Application (KOKAI) Publication No. 2002-266731 is provided with a filter element so as to divide the inside of the housing into a dirty side and a clean side. In the clean side, a plate-shaped adsorption element is arranged to be parallel with the filter element. An inner flanged portion extending toward the center side of the housing is formed along the entire inner peripheral surface of the housing. A pin for fusing is formed on one surface side of this inner flanged portion. The adsorption element has a frame to its peripheral edge portion, and an insertion hole is formed to the frame so as to conform with the fusing pin formed to the inner flanged portion.
The adsorption element is mounted to the housing by inserting the fusing pin into the insertion hole formed to the frame and crushing, by heating, the front end of the pin projecting over the frame surface to thereby calk the frame.
However, in the air cleaner disclosed in the publication 1, it is obliged to manufacture the adsorbing member specifically for such air-cleaner, and accordingly, the adsorbing member is not suitable for the general use. In addition, the adsorbing member may come off from the inner surface of the air cleaner if some countermeasure may not be considered.
On the other hand, in the air cleaner disclosed in the publication 2, at the time of attaching the adsorption element, it may be adversely influenced with heat for heating the pin. In addition, at the heating time of the pin, there may exist a fear of generation of welding residue from a front end of the fused pin, and moreover, in the air cleaner shown in this publication 2, since the adsorption element covers the whole air passage, air passing resistance will be increased, thus being inconvenient.
Furthermore, it is necessary to additionally take countermeasure to noise radiated from the air cleaner.